U.S. patent application number 11/040018 was filed with the patent office on 2005-08-18 for intravascular catheter with composite reinforcement.
This patent application is currently assigned to SciMed Life Systems, Inc.. Invention is credited to Anderson, Steven M., Bardsley, Earl, Dao, Cang D., Garabedian, Robert J., Griego, John, Schaefer, Dean A..
Application Number | 20050182388 11/040018 |
Document ID | / |
Family ID | 22880377 |
Filed Date | 2005-08-18 |
United States Patent
Application |
20050182388 |
Kind Code |
A1 |
Garabedian, Robert J. ; et
al. |
August 18, 2005 |
Intravascular catheter with composite reinforcement
Abstract
An intravascular catheter that exhibits the combined features of
superior flexibility, softness, radiopacity and oval/kink
resistance. The catheter includes an elongate shaft having a
proximal region, a distal region and a lumen extending
therethrough. The proximal region of the shaft includes an inner
lubricious polymer layer, a reinforcement layer and an outer layer.
The reinforcement layer comprises a braid having one or more
metallic members and a plurality of polymer members wherein each
polymer member comprises a plurality of monofilaments, preferably
formed of LCP. The polymer members of the braid provide improved
flexibility and softness in addition to high burst pressure. The
metallic member(s) of the braid provide improved radiopacity and
oval/kink resistance. The catheter may also include a longitudinal
member extending along the reinforcement layer.
Inventors: |
Garabedian, Robert J.; (West
Townsend, MA) ; Griego, John; (Blackstone, MA)
; Bardsley, Earl; (Newton, MA) ; Schaefer, Dean
A.; (Roslindale, MA) ; Dao, Cang D.; (Foxboro,
MA) ; Anderson, Steven M.; (Shrewsbury, MA) |
Correspondence
Address: |
CROMPTON, SEAGER & TUFTE, LLC
1221 NICOLLET AVENUE
SUITE 800
MINNEAPOLIS
MN
55403-2420
US
|
Assignee: |
SciMed Life Systems, Inc.
|
Family ID: |
22880377 |
Appl. No.: |
11/040018 |
Filed: |
January 19, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11040018 |
Jan 19, 2005 |
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10339055 |
Jan 9, 2003 |
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6866660 |
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10339055 |
Jan 9, 2003 |
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09684819 |
Oct 10, 2000 |
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6508805 |
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09684819 |
Oct 10, 2000 |
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09234203 |
Jan 20, 1999 |
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6171295 |
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Current U.S.
Class: |
604/527 |
Current CPC
Class: |
A61M 25/005 20130101;
A61M 25/0053 20130101 |
Class at
Publication: |
604/527 |
International
Class: |
A61M 025/00 |
Claims
What is claimed is:
1. An elongate shaft for use in a catheter, the elongate shaft
comprising: an inner layer defining a lumen; a reinforcement braid
layer disposed about the inner layer, the reinforcement braid layer
comprising at least one metallic member and a plurality of polymer
members, wherein each of the plurality of polymer members comprises
a plurality of monofilaments; and an outer polymer layer disposed
about the reinforcement braid layer, the outer polymer layer
including a proximal portion and a distal portion, wherein the
proximal portion of the outer polymer layer has a first durometer
hardness and the distal portion of the outer polymer layer has a
second durometer hardness less than the first durometer
hardness.
2. The elongate shaft of claim 1, wherein the plurality of
monofilaments of each polymer member are arranged to collectively
define a round cable.
3. The elongate shaft of claim 1, wherein the plurality of
monofilaments of each polymer member are arranged side-by-side to
collectively define a flat cable.
4. The elongate shaft of claim 1, wherein the plurality of
monofilaments of each polymer member are fused together.
5. The elongate shaft of claim 1, wherein the plurality of
monofilaments of each polymer member are not fused together.
6. The elongate shaft of claim 1, wherein the elongate shaft
includes a distal end, wherein a tip layer having a third durometer
hardness less than the second durometer hardness is disposed at the
distal end of the elongate shaft.
7. The elongate shaft of claim 1, further comprising a longitudinal
member extending along the reinforcement braid layer.
8. The elongate shaft of claim 7, wherein the longitudinal member
includes a plurality of monofilaments.
9. A catheter comprising: an inner layer defining a lumen; a
reinforcement braid layer disposed about the inner layer, the
reinforcement braid layer comprising at least one metallic member
and a plurality of polymer members, wherein each of the plurality
of polymer members comprises a plurality of monofilaments; a
longitudinal member extending along the reinforcement braid layer;
and an outer layer disposed about the reinforcement braid
layer.
10. The catheter of claim 9, wherein the outer layer includes a
first portion having a first durometer hardness and a second
portion having a second durometer hardness less than the first
durometer hardness.
11. The catheter of claim 10, wherein the outer layer includes a
gradual transition between the first durometer hardness and the
second durometer hardness.
12. The catheter of claim 9, wherein the plurality of monofilaments
of each polymer member are arranged to collectively define a round
cable.
13. The catheter of claim 9, wherein the plurality of monofilaments
of each polymer member are arranged side-by-side to collectively
define a flat cable.
14. The catheter of claim 9, wherein the plurality of monofilaments
of each polymer member are fused together.
15. The catheter of claim 9, wherein the plurality of monofilaments
of each polymer member are not fused together.
16. The catheter of claim 9, wherein the inner layer comprises a
lubricious polymer.
17. The catheter of claim 9, further comprising a tie layer
disposed between the inner layer and the reinforcement braid layer
and securing the reinforcement braid layer to the inner layer.
18. The catheter of claim 9, wherein the reinforcement braid layer
includes a distal end, wherein a tip layer is disposed at the
distal end of the reinforcement braid layer and extends distal of
the reinforcement braid layer.
19. The catheter of claim 9, wherein the longitudinal member
includes a plurality of monofilaments.
20. The catheter of claim 19, wherein the plurality of
monofilaments of the longitudinal member comprise a liquid crystal
polymer.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of co-pending U.S.
application Ser. No. 10/339,055, filed Jan. 9, 2003; which is a
continuation of U.S. application Ser. No. 09/684,819, filed Oct.
10, 2000, now U.S. Pat. No. 6,508,805; which is a continuation of
U.S. application Ser. No. 09/234,203, filed Jan. 10, 1999, now U.S.
Pat. No. 6,171,295, the disclosures of which are all incorporated
herein by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention generally relates to intravascular
devices. More specifically, the present invention relates to
reinforced intravascular catheters.
[0003] Intravascular catheters are used in a wide variety of
relatively non-invasive medical procedures. Such intravascular
catheters may be used for diagnostic or therapeutic purposes.
Generally, an intravascular catheter allows a physician to remotely
perform a medical procedure by inserting the catheter into the
vascular system of the patient at a location that is easily
accessible and thereafter navigating the catheter to the desired
target site. By this method, virtually any target site in the
patient's vascular system may be remotely accessed, including the
coronary, cerebral, and peripheral vasculature.
[0004] The distance between the access site and the target site is
often in excess of 100 cm. The inside diameter of the vasculature
at the access site is often less than 2 cm, and the inside diameter
of the vasculature at the target site is often less than 0.5 cm.
Accordingly, intravascular catheters must be relatively long and
thin. Furthermore, in order to navigate through the patient's
tortuous vascular system, intravascular catheters must be very
flexible. It is also desirable that intravascular catheters be
relatively soft in order to minimize the probability of damaging
vascular tissue.
[0005] Intravascular catheters typically have a radiopaque portion
and are guided through the patient's vascular system with the
assistance of x-ray fluoroscopy. In this manner, a physician may
manipulate the proximal end of the catheter and fluoroscopically
monitor the corresponding movement of the distal end of the
catheter. As such, it is desirable that intravascular catheters be
sufficiently radiopaque along their length and particularly at
their distal end such that the physician is able to clearly monitor
the progress of the catheter as it is being advanced from the
vascular access site to the vascular target site.
[0006] After the intravascular catheter has been navigated through
the patient's vascular system with the distal end thereof adjacent
the target site, the catheter may be used for various diagnostic
and/or therapeutic purposes. Frequently, diagnostic and therapeutic
techniques require the infusion of fluids through the catheter. For
example, it may be desirable to inject radiopaque contrast media
through the catheter to provide enhanced fluoroscopic visualization
for diagnostic purposes, or to inject pharmaceutical solutions
(i.e., drugs) to the target site for therapeutic purposes. In order
to maintain a fluid path, it is desirable that intravascular
catheters be sufficiently resistant to kinking. In addition,
because such fluids are delivered under pressure, it is also
desirable that intravascular catheters be sufficiently resistant to
bursting.
[0007] To satisfy some of these desirable features, prior art
intravascular catheters have utilized a reinforcement structure
such as a braid or coil disposed between an inner lubricious
tubular layer and an outer flexible tubular layer. A braid
reinforcement structure offers high resistance to bursting and
improves the connection integrity between individual shaft
segments. However, braid reinforcement offers limited resistance to
ovaling, which is a precursor to kinking. A coil reinforcement
structure, by contrast, provides adequate resistance to ovaling and
kinking, but does not sufficiently enhance the connection integrity
between individual shaft segments.
SUMMARY OF THE INVENTION
[0008] The present invention overcomes these disadvantages by
providing an intravascular catheter that exhibits the combined
features of superior flexibility, softness, radiopacity,
durability, high burst strength, and oval/kink resistance.
[0009] An intravascular catheter in accordance with one embodiment
of the present invention includes an elongate shaft having a
proximal region, a distal region and a lumen extending
therethrough. The proximal region of the shaft includes an inner
lubricious polymer layer, a reinforcement layer and an outer layer.
The reinforcement layer comprises a braid having at least one
metallic member and a plurality of polymer members wherein each
polymer member comprises a plurality of monofilaments. The
monofilaments may be made of LCP having a substantially circular
cross-section and may be unfused or fused together. The
monofilaments may be arranged side-by-side to collectively define a
flat cable that may be twisted along the length of the shaft. The
metallic member(s) may be made of a highly radiopaque material. The
catheter may further include a longitudinal member extending along
the reinforcement layer. The longitudinal member may also comprise
a plurality of longitudinal monofilaments made of a polymer, such
as LCP. The distal region of the shaft may include a radiopaque
marker band surrounding the reinforcement layer and an atraumatic
tip layer surrounding a portion of the radiopaque marker band and a
portion of the reinforcement layer. The tip layer may extend
distally beyond the distal ends of the inner layer and the
reinforcement layer to form an atraumatic soft distal tip.
[0010] The brand reinforcement provides high burst strength and
durability. The polymer members of the braid provide enhanced
flexibility and softness, and the metallic members(s) of the braid
provide enhanced radiopacity and resistance to ovaling and kinking.
These combined features are not found in the prior art.
[0011] An intravascular catheter in accordance with another
embodiment of the present invention includes an elongate shaft
having a proximal region, a distal region and a lumen extending
therethrough. The proximal region of the shaft includes an inner
lubricious polymer layer, a reinforcement layer and an outer layer.
The outer layer includes a proximal portion made of a first
material having a first durometer, and a distal portion made of a
second material having a second durometer less than the first
durometer. The reinforcement layer comprises a braid having one or
more metallic members and a plurality of polymer members wherein
each polymer member comprises a plurality of monofilaments. The
distal region of the shaft includes a radiopaque marker band
surrounding the reinforcement layer and an atraumatic tip layer
surrounding the radiopaque marker band and the reinforcement layer.
The tip layer is made of a third material having a third durometer
less than the second durometer. The tip layer includes a distal
portion that extends beyond the distal ends of the inner layer and
the reinforcement layer to form an atraumatic soft distal tip.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a plan view of an intravascular catheter in
accordance with the present invention;
[0013] FIG. 2 is a partially sectioned detailed view of the
elongate shaft of the intravascular catheter illustrated in FIG. 1.
Specifically, the outer layer has been removed on the top portion
of the shaft to expose the reinforcement layer and the radiopaque
marker band. In addition, the bottom portion has been sectioned to
expose the various layers of the shaft;
[0014] FIG. 3 is a cross-sectional view taken along line 3-3 in
FIG. 1;
[0015] FIG. 4 is an alternative embodiment of the shaft illustrated
in FIG. 2; and
[0016] FIGS. 5A and 5B are cross-sectional views of the polymer
member of the reinforcement layer illustrated in FIGS. 2-4.
DETAILED DESCRIPTION OF THE INVENTION
[0017] The following detailed description should be read with
reference to the drawings in which similar elements in different
drawings are numbered the same. The drawings, which are not
necessarily to scale, depict illustrative embodiments and are not
intended to limit the scope of the invention.
[0018] FIG. 1 illustrates intravascular catheter 10 in accordance
with the present invention. Catheter 10 includes an elongate shaft
12 having a proximal region 14 and a distal region 16. The catheter
10 includes a lumen 18 (as best seen in FIG. 3) extending through
the entire length of the elongate shaft 12 to an opening at the
distal end 20 of the shaft 12. Catheter 10 may have a length of 80
to 150 cm and an outside diameter of approximately 3 F.
[0019] A manifold 24 is connected to the proximal end 22 of the
shaft 12 which includes an interior (not visible) in fluid
communication with the lumen 18 of the elongate shaft 12. Manifold
24 includes a standard fitting 26 for connection to a fluid source
such as a syringe. A strain relief 28 is disposed between the
manifold 24 and the proximal end 22 of the shaft 12 in order to
reduce the tendency of the shaft to kink therebetween. The proximal
end 22 of the elongate shaft 12 may extend through the strain
relief 28 for connection to the manifold 24. Alternatively, the
distal end of the strain relief 28 may be connected to the proximal
end 22 of the elongate shaft 12 with the proximal end of the strain
relief 12 connected to the manifold 24.
[0020] With either arrangement, the intravascular catheter 10
provides a fluid path from the fitting 26 of the manifold 24 to the
distal end 20 of the elongate shaft 12 by way of the interior (not
visible) of the manifold 24 and the lumen 18 of the elongate shaft
12. This intravascular catheter 10 may be advanced over a guide
wire and used to deliver diagnostic and/or therapeutic fluids to a
desired vascular target site using conventional techniques.
[0021] FIG. 2 is a partially sectioned detailed view of the
elongate shaft 12 of the intravascular catheter 10 illustrated in
FIG. 1. On the top portion of the shaft 12, the outer layer 30 has
been removed to expose the reinforcement layer 32 and the
longitudinal member 34. On the bottom portion, the shaft 12 has
been sectioned to illustrate the various layers 30, 32, 36, and 38
of the shaft 12.
[0022] Elongate shaft 12 includes a proximal region 14 and a distal
region 16. Both the proximal region 14 and a portion of the distal
region 16 include an inner lubricious polymer layer 36 surrounded
by a reinforcement layer 32 which, in turn, is surrounded by an
outer layer 30. The outer layer 30 may be loaded with a radiopaque
contrast material such as barium sulfate, preferably loaded at 30%
by weight. A tie layer 38 may be provided between the reinforcement
layer 32 and the inner lubricious layer 36. Each of these layers
are most clearly illustrated on the bottom portion of the shaft 12
shown in FIG. 2 and the cross-sectional view taken along line 3-3
as shown in FIG. 3.
[0023] Inner layer 36 is formed of a lubricious polymer such as
PTFE or HDPE and preferably has a relatively thin wall to minimize
profile. Inner layer 36 has an inside diameter sufficiently large
to accommodate a conventional guidewire and to accommodate the
delivery of fluids therethrough at a sufficient flow rate. For
example, the inside diameter of the inner layer 36 may be
approximately 0.027 inches and the wall thickness of the inner
layer 36 may be approximately 0.0005 inches. The inner layer 36 may
be formed, for example, by coating or extruding a lubricious
polymer such as PTFE over a removable mandrel, or by using other
known manufacturing techniques.
[0024] As mentioned previously, a tie layer 38 may be utilized to
secure the reinforcement layer 32 to the inner lubricious layer 36.
Tie layer 38 enhances the bond between the inner lubricious layer
36, the reinforcement layer 32, and the outer layer 30. Tie layer
38 also fills any micro-pores that may form in the inner layer 36
to thereby increase burst strength. Further, tie layer 38 maintains
the position of the reinforcement layer 32 on the inner layer 36
during the manufacturing process. The thickness of the tie layer 38
may be approximately 0.0003 inches to reduce the corresponding
increase in profile. An example of a suitable material for tie
layer 38 is polyurethane, which may be coated onto the inner
lubricious layer 36.
[0025] Reinforcement layer 32 comprises a plurality of braided
polymer members 40 and one or more metallic members 42. For
example, the reinforcement layer 32 in the form of a braid having a
total of eight members may comprise six polymer members 40 and two
metallic members 42. Those skilled in the art will recognize that
the braid reinforcement layer 32 may vary in pattern, strand
quantity, pick-count, etc., without departing from the scope of the
present invention.
[0026] Each polymer member 40 comprises a plurality of
monofilaments 41 to collectively define a cable 40A or 40B,
illustrated in FIGS. 5A and 5B, respectively. FIGS. 5A and 5B show
cross-sectional views of the polymer cables 40A and 40B of the
reinforcement layer. FIG. 5A illustrates a round cable 40A, and
FIG. 5B illustrates a flat cable 40B.
[0027] The monofilaments 41 may be unfused or fused together
depending on the desired characteristics. If the monofilaments 41
are fused together, the polymer member 40 has mechanical
characteristics similar to that of a solid rod. If the
monofilaments 41 are not fused together, the polymer member 40 has
mechanical characteristics similar to that of a cable. A cable, as
opposed to a solid rod, is more flexible and is able to withstand
more fatigue due to repeated bending. As such, a reinforcement
layer 32 utilizing braided polymer members 40 comprising a
plurality of unfused monofilaments 41 provide a shaft 12 that is
more flexible and more durable. These features are significant
because the catheter 10 must be able to navigate tortuous
vasculature and withstand harsh handling conditions.
[0028] The monofilaments 41 may be made of a liquid crystal polymer
(LCP) available under the trade name VECTRAN. Each monofilament may
have a circular cross-section having a diameter of 0.0007 inches.
Each polymer member 40 may comprise two (2) to ten (10), and
preferably five (5) monofilaments 41 which, as stated previously,
may be fused or unfused. If the monofilaments 41 are unfused, the
monofilaments of the polymer member 40 are typically arranged
side-by-side to essentially define a flat cable 40B as shown in
FIG. 5B. It is possible, however, that the monofilaments be
arranged in any manner to collectively define a flat cable 40B, a
round cable 40A, or any other desired geometry.
[0029] Furthermore, if the monofilaments are arranged to
collectively define a flat cable 40B, the flat cable 40B may be
twisted along the length of the catheter shaft 12. Specifically,
the flat cable 40B has a pair of major sides 43 and a pair of minor
sides 45. Each of the major sides 43 faces the lumen 18 at various
points along the length of the shaft 12. The flat cable may have
random twists or a twist every 7.5 inches, depending on
manufacturing conditions. Twisting the flat cable 40B may provide
the advantage of improved guide wire movement due to ridges formed
on the inside surface of the inner layer 36.
[0030] The metallic member 42 may be formed of stainless steel or a
highly radiopaque material such as gold, tungsten, iridium, or an
alloy thereof. If a plurality of metallic members 42 is utilized,
one or more of the metallic members 42 may comprise stainless steel
to provide superior strength and one or more metallic members 42
may comprise a highly radiopaque material to provide enhanced
radiopacity. Although stainless steel provides higher radiopacity
relative to most polymers, a more dense material such as those
identified above is preferred for purposes of radiographic
visualization. The metallic members 42 may have a rectangular
cross-section or a circular cross-section, depending on the desired
mechanical characteristics. Metallic member 42 may have a circular
cross-section with a diameter of approximately 0.0016 inches to
minimize profile.
[0031] Longitudinal member 34 is disposed between the reinforcement
layer 32 and the tie layer 38 to provide enhanced resistance to
elongation as the catheter 10 is removed from the patient's body.
Longitudinal member 34 may be an LCP flat cable, similar to cable
40B.
[0032] When the polymer members 40 and the metallic member(s) 42
are braided, the reinforcement layer 32 provides superior
flexibility and softness by virtue of the polymer members 40 in
addition to superior radiopacity and kink resistance by virtue of
the metallic member(s) 42. These combined features are not found in
prior art intravascular devices.
[0033] The proximal region 14 of shaft 12 includes an outer layer
30 formed by interrupted layer coextrusion (ILC) as described in
U.S. Pat. No. 5,622,665 to Wang, which is hereby incorporated by
reference. The ILC portion 44 of outer layer 30 includes a proximal
portion 47 formed of a relatively high durometer polymer and a
distal portion 49 formed of a relatively low durometer polymer. By
virtue of the ILC process, the proximal region 14 gradually
transitions from the relatively high durometer polymer 47 to the
relatively low durometer polymer 49. The transition between the
relatively high durometer polymer 47 to the relatively low
durometer polymer 49 is graphically illustrated by transition line
46. However, transition line 46 is typically not visible due to the
intermixing of polymers during the ILC process. The ILC portion 44
may be formed of a suitable polymer such as polyether block amide
having a wall thickness of approximately 0.0025 inches. For
example, the proximal ILC portion 47 may be formed of PEBAX.TM.
7233, which has a durometer of 72 D and the distal ILC portion 49
may be formed of PEBAX.TM. 3533 having a durometer of 35 D.
[0034] The proximal region 14 of the outer layer 30 abuts the
distal region 16 of the outer layer 30 at junction line 48. The
distal region 16 of the shaft 12 includes a proximal portion 50 and
a distal portion 52. Both the proximal portion 50 and the distal
portion 52 of the distal region 16 may be formed of the same or
different polymers which have a durometer less than the durometer
of the distal portion 49 of the ILC section 44. The distal portion
52 of the distal region 16 may have the same or lower durometer
than the durometer of the proximal portion 50. The proximal portion
50 and the distal portion 52 may be formed of a polyether block
amide polymer such as PEBAX.TM. 2533 having a durometer of 25 D.
The proximal portion 50 encapsulates the radiopaque marker band
60.
[0035] Radiopaque marker band 60 may be formed of gold, tungsten,
iridium, or an alloy thereof. The radiopaque marker band 60 is
disposed over the reinforcement layer 32 and may optionally be
swaged onto the reinforcement layer 32. The radiopaque marker band
60 may optionally be adhesively secured to the reinforcement layer
32 or held in place by the encapsulating proximal portion 50.
[0036] The distal portion 52 of the distal region 16 abuts the
distal ends of the various layers 36, 38, and 32 and forms a lap
joint with proximal portion 50 along junction line 54. Junction
line 54 between the proximal portion 50 of the outer layer 30 and
the distal portion 52 is not present if the proximal portion 50 and
the distal portion 52 are made of the same material, i.e., the
proximal portion 50 and the distal portion 52 form a single unitary
piece. Encapsulated marker band 60 may have a length of
approximately 1.0 mm and may be positioned approximately 0.5 to 1.5
mm proximal of the distal end of the shaft 12. Distal portion 52
may extend approximately 0.5 to 1.0 mm beyond the distal end of the
inner layer 36, tie layer 38 and reinforcement layer 32 to form an
atraumatic soft tip.
[0037] FIG. 4 is an alternate embodiment of the elongate shaft 12
illustrated in FIG. 2. Specifically, FIG. 4 illustrates an
alternative arrangement of the outer layer 30 of the distal region
16 of the elongate shaft 12. Except as described herein, all
aspects of the embodiment illustrated in FIG. 4 are the same as
those described with reference to the embodiment illustrated in
FIG. 2.
[0038] Distal region 16 includes a proximal portion 70 and a distal
portion 72. Proximal portion 70 and distal portion 72 may be formed
of the same materials as proximal portion 50 and distal portion 52,
respectively, as described with reference to FIG. 2. Distal portion
72 encapsulates the outer surface and distal face of the marker
band 60. Distal portion 72 and proximal portion 70 are connected by
a lap joint as defined by junction line 74. Junction line 74
between the proximal portion 70 and the distal portion 72 is not
present if the proximal portion 70 and the distal portion 72 are
formed of the same or similar materials. Distal portion 72 is
approximately 2.5 to 3.0 mm in length and extends approximately 1.0
mm beyond the distal ends of the inner layer 36, the tie layer 38,
and the reinforcement layer 32 to form an atraumatic tip.
[0039] The elongate shaft 12, including the embodiment illustrated
in FIG. 2 and the embodiment illustrated in FIG. 4, may be
manufactured by a number of suitable manufacturing processes
including the process described hereinafter. The inner layer 36 and
the tie layer 38 may be obtained prefabricated from a suitable
vendor, such as H.V. Technologies, and provided as discrete tubes
or on a spool as a continuous tube. Longitudinal member 34 is then
disposed on the tube of inner layer 36 and tie layer 38.
Optionally, the longitudinal member 34 may be applied during the
braiding step. The reinforcement layer 32 is then braided over the
longitudinal member 34 and the tube of inner layer 36 and tie layer
38. The braided subassembly is subsequently cut to the desired
length. The marker band 60 is slid over the reinforcement layer 32
into position adjacent the distal end 20 of the elongate shaft 12.
The proximal portion 50,70 of the distal region 16 is slid over the
reinforcement layer 32 adjacent the marker band 60. The proximal
region 14 comprising a prefabricated ILC tube 44 is slid over the
proximal end 22 of the elongate shaft 12. A heat shrink tube (e.g.,
FEP) is then placed over the shaft 12 components and the composite
subassembly is pulled through a heated die. The die is heated to
380.degree.-430.degree. F. causing the components of the shaft 12
to be fused and compressed together by the combined heat and radial
force. The heat shrink tube is then removed, exposing the completed
shaft 12 subassembly. The manifold 24 and the strain relief 28 are
then attached to the proximal end 22 of the elongate shaft 12 using
conventional techniques. The catheter 10 is then tested for minimum
performance criteria including burst pressure. The distal end 20 of
the elongate shaft 12 is then trimmed to the desired length, and
the distal portion 52,72 of the distal region 16 is thermally fused
thereto by, for example, inserting a mandrel into the lumen 18 and
heating the tip 20 at 350.degree. F. for twenty-six (26) seconds. A
lubricious coating is then applied to exterior of the catheter
shaft 12.
[0040] Those skilled in the art will recognize that the present
invention may be manifested in a variety of forms other than the
specific embodiments described and contemplated herein.
Accordingly, departures in form and detail may be made without
departing from the scope and spirit of the present invention as
described in the appended claims.
* * * * *